The factors or conditions that will change as a result of the independent variable
- 1. Types of variables Chapter 4 part 1
- 2. What is a Variable?
- 3. DEFINITION Variable – Any factor that can change in a scientific investigation or experiment
- 4. • The purpose of experiments is to determine how the variables affect each other.
- 5. Types of Variables Independent Variable (also called the manipulated variable) The condition that is intentionally changed by the investigator in an experiment There can be only one independent variable in an experiment
- 6. Dependent Variable (also called the responding variable) The factors or conditions that will change as a result of the independent variable The factors that you measure or observe as data There can be one or more dependent variables in an experiment Types of Variables
- 7. Controlled Variables The factors or conditions that are kept the same (unchanged) in an experiment. There are many controlled variables in an experiment Types of Variables
- 8. Identify variables for the following experiments. You can do it! Practice
- 9. • Does changing the temperature of a ball affect the height the ball will bounce? Testable Question #1 Hot Cold
- 10. Manipulated Variable Responding Variable Identify Variables #1 Cold Hot • Does changing the temperature of a ball affect the height the ball will bounce?
- 11. • Controlled Variables: * Same ball * Dropped from the same height * Dropped onto the same surface * etc… Identify Variables #1
- 12. • Does changing the color of light affect the growth rate of plants? Testable Question #2
- 13. Manipulated Variable Responding Variable Identify Variables #2 • Does changing the color of light affect the growth rate of plants?
- 14. • Controlled Variables: * Same type / size of plant * Same amount of water * Same soil * Light on for the same amount of time * etc… Identify Variables #2
- 15. Example 1 A dentist wanted to determine which brand of toothpaste would make teeth whiter. He gave his patients Crest and Oral B. The patients brushed for the same amount of time, used the same amount of toothpaste and had their teeth checked each week. • Independent variable___________________ • Dependent variable _____________________ • Controlled variable _____________________
- 16. Answers to Example 1 • Independent variable • Toothpaste • Dependent variable • Whiter teeth • Controlled variable • Same amount of toothpaste, same amount of time brushing their teeth, and getting their teeth checked.
- 17. Example 2 A scientist wanted to determine if eating carrots would help peoples vision. For each meal one group of people ate carrots while the other group didn’t. All of the people ate at the same time and place. • Independent variable_______ • Dependent variable ________ • Controlled variable _________
- 18. Answers to Example 2 • Independent variable • Eating carrots • Dependent variable • Improved vision • Controlled variable • Eating at the same time and place
- 19. The table below summarizes independent variables, dependent variables, and control variables. Types of variables in research Explanation Example Independent/ treatment variables The variables you manipulate to affect the experiment outcome Dependent/ response variables The variable that represents the experiment outcomes Control variables Variables held constant throughout the study
- 20. • Independent Variables and Dependent Variables in a Study on Sociodemographic and Clinical Prediction of Response of Major Depressive Disorder to Antidepressant Drug Treatment
- 21. Combinations of Age with Dependent Variables in the Generation of Hypotheses • In patients with major depressive disorder who are treated with antidepressant drugs